1. Field of the Invention
The present invention relates to air conditioning garments for individuals under extreme environmental conditions. In particular, the present invention relates to garments such as suits, vests, helmets and parts thereof, for racecar drivers, motorcycle drivers and pilots.
2. Discussion of the Related Art
In a clear day, with ambient temperature of 25 degrees Celsius, cabin temperature may reach 40 degree Celsius and more. Excess heat, when vehicle operators are not aware of their judgment being affected by the harsh conditions, seems to be the cause of numerous accidents.
The major traditional technologies used for air conditioning are air-cycle and vapor-cycle. Air-cycle air-conditioning works by the use of high-pressure air that is accelerated and allowed to expand rapidly, thus exchanging heat with surrounding area and cooling the air. This technology is used primarily for the air-conditioning of large transport aircraft and jet airplanes, where a large volume of pressurized air is available. Vapor-cycle air conditioning, which is the most common technology, exploits the use of a compressor and refrigerant liquid/gas to perform a heat exchange process with the surrounding air, thus cooling the environment.
Such traditional systems, which are used to cool an enclosed space, for instance an entire vehicle's cabin, are not fit for use in special vehicles such as closed-cockpit racecars and small aircraft because of weight and energy consumption considerations. The units used by traditional methods are heavy, in the range of 30–40 kg. This is an extensive and unacceptable added weight to a racecar or a small aircraft, which seriously impedes their performance. Standard air-conditioning units also require a large energy source, which is usually taken from the vehicle's power plant and might consume about 5% of the engine power. This is a negative factor to racecars drivers and owners, needing every bit of engine power. Thus, standard units do not fit for use in vehicles where power consumption demands may reduce performance. Furthermore, standard air-conditioning systems involve high expenses and their installation increases the burden and cost of the racecar or aircraft manufacturing.
The approach taken by the present invention is to air condition the individual rather than the environment. Such an approach fits individuals under extreme environmental conditions such as racecar drivers, motorcycle drivers and pilots mentioned above as well as people who wear protective garments such as fire fighters etc.
Various “personal air conditioning systems” for air conditioning an individual by especially designed garments are known in the art. Such air conditioning systems can be classified as liquid-based systems or gas-based systems. Liquid-based systems employ closed system circulation of cooled liquids and cool by touch. Gas-based systems cool by gas expansion. Both methods employ a system of tubing passing in the proximity of the wearer body for conveying the liquid or gas either in a closed or in an open system.
Existing personal conditioning systems suffer from a number of drawbacks. Conditioning systems which are using liquid circulation in a closed system might be dangerous if upon malfunctioning, liquids stop circulating. In such a case, the isolated liquid layer would heat up and prevent the body from “breathing”, thus worsening users physical and psychological situation, which may end in a “heat-shock”. Furthermore, liquid systems are susceptible to liquid leakage which might cause inconvenience to the wearer and damage to equipment.
Another main drawback associated with tubing-based systems, for conveying either gas or liquid, is that upon wearer movements tubes might fold and block passage of fluids. On the other hand, if the tubes are made of relatively rigid material for preventing the tubes from folding, then the tubing system imparts the garment rigidity which might limit the wearer's movements. Wearer convenience considerations also limits the diameter of the tubing that can be used, therefore a relatively high pressure in needed in order to obtain reasonable flow rate. Another drawback of tubing systems is that with time tubes tend to get plugged due to precipitant accumulation on the tubing walls.
Accordingly, it is the object of the present invention to provide a personal air conditioning system, which overcomes the drawbacks of known systems.